Transcriptomic analysis of tobacco-flavored E-cigarette and menthol-flavored E-cigarette exposure in the human middle ear

Electronic cigarettes (e-cigarettes) are the most widely used electronic nicotine delivery systems and are designed to imitate smoking and aid in smoking cessation. Although the number of e-cigarette users is increasing rapidly, especially among young adults and adolescents, the potential health impacts and biologic effects of e-cigarettes still need to be elucidated. Our previous study demonstrated the cytotoxic effects of electronic liquids (e-liquids) in a human middle ear epithelial cell (HMEEC-1) line, which were affected by the manufacturer and flavoring agents regardless of the presence of nicotine. In this study, we aimed to evaluate the gene expression profile and identify potential molecular modulator genes and pathways in HMEEC-1 exposed to two different e-liquids (tobacco- and menthol-flavored). HMEEC-1 was exposed to e-liquids, and RNA sequencing, functional analysis, and pathway analysis were conducted to identify the resultant transcriptomic changes. A total of 843 genes were differentially expressed following exposure to the tobacco-flavored e-liquid, among which 262 genes were upregulated and 581 were downregulated. Upon exposure to the menthol-flavored e-liquid, a total of 589 genes were differentially expressed, among which 228 genes were upregulated and 361 were downregulated. Among the signaling pathways associated with the differentially expressed genes mediated by tobacco-flavored e-liquid exposure, several key molecular genes were identified, including IL6 (interleukin 6), PTGS2 (prostaglandin-endoperoxide synthase 2), CXCL8 (C-X-C motif chemokine ligand 8), JUN (Jun proto-oncogene), FOS (Fos proto-oncogene), and TP53 (tumor protein 53). Under menthol-flavored e-liquid treatment, MMP9 (matrix metallopeptidase 9), PTGS2 (prostaglandin-endoperoxide synthase 2), MYC (MYC proto-oncogene, bHLH transcription factor), HMOX1 (heme oxygenase 1), NOS3 (nitric oxide synthase 3), and CAV1 (caveolin 1) were predicted as key genes. In addition, we identified related cellular processes, including inflammatory responses, oxidative stress and carcinogenesis, under exposure to tobacco- and menthol-flavored e-liquids. We identified differentially expressed genes and related cellular processes and gene signaling pathways after e-cigarette exposure in human middle ear cells. These findings may provide useful evidence for understanding the effect of e-cigarette exposure.

Comparison between in vitro toxicities of tobacco- and menthol-flavored electronic cigarette liquids on human middle ear epithelial cells

Since electronic-cigarettes (e-cigarettes) are considered less toxic than conventional tobacco smoking, the use of e-cigarettes has increased, and the market for e-cigarette liquids (e-liquids) is continuously increasing. However, many studies showed that e-cigarettes may cause various harmful effects in lung, oral and heart. In this study, we investigated the effects of e-liquids on otitis media (OM) using human middle ear epithelial cells (HMEECs). Menthol-flavored e-liquid induced significant cell death in HMEECs (IC50: 1.45 ± 0.14%) and tobacco-flavored e-liquid led to increase in inflammatory cytokine levels and higher mucin production. Flavored e-liquids decreased the mRNA levels of genes encoding epithelial sodium channels (ENaCs) in HMEECs. Apoptosis and autophagy reactions were induced by exposure of HMEECs to menthol- and tobacco-flavored e-liquids. Tobacco-flavored e-liquids caused a greater increase in the levels of autophagosome marker, LC3-II, compared to menthol-flavored e-liquids, which was followed by cell death. These results demonstrate that flavored e-liquids cause cytotoxicity via apoptosis, autophagy, inflammatory response, and mucin production in HMEECs. The flavors present in e-liquids might be a risk factor for the development of otitis media.

Gentamicin delivery to the inner ear: Does endolymphatic hydrops matter?

Introduction

Middle ear application of gentamicin is a common medical treatment for uncontrolled Ménière’s disease. The objective of the study was to evaluate the impact of endolymphatic hydrops on inner ear delivery.

Methods

Perilymph gentamicin concentrations and correlation with endolymphatic hydrops in an animal model were assessed. A group of 24 guinea pigs was submitted to surgical obstruction of the endolymphatic sac and duct of the right ear. Gentamicin was applied either to the right ear’s round window niche or through a transtympanic injection. Perilymph specimens were collected at different times. Histologic morphometry was used to evaluate both turn-specific and overall hydrops degree.

Results

In animals with endolymphatic hydrops, lower concentrations of gentamicin were observed after 20 or 120 minutes of exposure and in both types of administration, when compared to controls. This difference reached statistical significance in the round window niche application group (Mann-Whitney, p = 0,007). A negative correlation between perilymphatic gentamicin concentration and hydrops degree could be observed in both groups, after 120 minutes of exposure (Spearman correlation, round window niche p<0,001; TT p = 0,005).

Conclusions

The study indicates that the endolymphatic hydrops degree has a negative interference on the delivery of gentamicin into the inner ear following middle ear application.

Efficacy of oral vs. intratympanic corticosteroids in sudden sensorineural hearing loss

BACKGROUND

The current standard treatment for sudden sensorineural hearing loss (SSNHL) comprises of tapered course of oral corticosteroids. Intratympanic steroids are introduced as another modality of treatment, but management of SSNHL continues to be debatable. The present study was designed to evaluate the efficacy of steroids given orally and by the intratympanic route.

METHODS

A prospective, randomized, open-labeled study was conducted involving 42 patients. These were randomly divided into two groups; group I patients received oral prednisone tapered over 14 days, and group II patients were treated with intratympanic methylprednisolone (40 mg/mL). One milliliter of the drug solution containing 40 mg of the drug (40 mg/mL) was injected into the middle ear cavity through the trans-tympanic route. The drug was injected twice a week for 2 weeks. The total duration of the study was 60 days, and hearing outcome was assessed on the basis of change in pure tone average.

RESULTS

An improvement of 18.24±8.72 dB was recorded in group I patients treated with oral prednisone in comparison to 14.68±12.88 dB improvement in group II. Statistically significant improvement in hearing was observed in both groups, but it was not significant when group I and group II were compared.

CONCLUSIONS

The post-treatment outcomes among patients who receive either oral prednisone or intratympanic methylprednisolone within 2 weeks of onset of symptoms were comparable. The outcomes were affected by degree of hearing loss and association of SSNHL with vertigo.

Comparison of Serotype Prevalence of Pneumococci Isolated from Middle Ear, Lower Respiratory Tract and Invasive Disease Prior to Vaccination in Iceland

Background

Information on pneumococcal serotype distribution before vaccination is a prerequisite for evaluation of vaccine effect. The aim was to investigate the prevalence of pneumococcal serotypes isolated from middle ear (ME), lower respiratory tract (LRT) and from invasive disease (IPD) in Iceland prior to implementation of ten-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine (PHiD-CV-10) into the infant vaccination program (April 2011).

Methods and findings

All isolates cultured 2007–2011 from ME, LRT and IPD identified as pneumococci were serotyped and tested for susceptibility at the Clinical Microbiology Department, Landspitali University Hospital that serves approximately 85% of the Icelandic population. Pneumococcal isolates were 1711 and 1616 (94.4%) were available for serotyping and included. Isolates belonging to PHiD-CV10 serotypes (VTs) were 1052 (65.1%). Isolates from ME were 879 (54.4%), with 639 (72.7%) from 0–1 year old patients and 651 of VTs (74%). Isolates from LRT were 564 (34.9%), with 292 (51.8%) from ≥65 years old patients, and 300 (53.2%) of VTs. IPD isolates were 173 (10.7%), although more evenly distributed according to age than isolates from the other sites most were from adults and the youngest age group,101 (58.4%) isolates were of VTs. The most common serotype was 19F, 583 (36.1%). Its prevalence was highest in ME, 400 (45.5%), 172 (30.5%) in LRT and 11 isolates (6.4%), in IPD. Penicillin non-susceptible isolates were 651 (40.3%), mainly belonging to VTs, 611 (93.9%), including 535 (82.2%) of 19F.

Conclusions

Multiresistant isolates of serotype 19F were highly prevalent, especially from ME of young children but also from LRT of adults. Serotype 14 was the most common serotype in IPD. The rate of VTs was high and almost all PNSP were of VTs. There was great difference in vaccine coverage between sampling sites, also reflecting difference in vaccine coverage by age groups.

The Effect of Dexmedetomidine on Middle Ear Pressure

OBJECTIVE: Dexmedetomidine is a preferred anesthetic agent in otological surgery because it provides controlled hypotension and good surgical field visibility. The aim of this study was to evaluate the influence of this novel agent on middle ear pressure.

STUDY DESIGN AND SETTING: This prospective clinical trial was performed in 60 patients who were scheduled for elective surgery. They received dexmedetomidine or saline infusion for 20 minutes before induction of anesthesia. Tympanometric measurements were recorded for both ears at preoperative, intraoperative, and postoperative states.

RESULTS: Mean difference of tympanometric peak pressure from baseline was statistically significant between dexmedetomidine and control group at the 30th minute of operation (24.8 daPa, P = 0.003 for right ear; 20.5 daPa, P = 0.02 for left ear) and at the end of the operation (25.8 daPa, P = 0.01 for right ear; 28.1 daPa, P = 0.004 for left ear).

CONCLUSIONS: Dexmedetomidine anesthesia raises the tympanometric parameters, but they never exceed the limits of normal.

Effect of systemic clarithromycin and prednisolone on histamine-induced otitis media in guinea pigs

CONCLUSION

The results of the study showed that clarithromycin has anti-inflammatory and antioxidant effects and, when it is combined with prednisolone, those effects gain strength.

OBJECTIVES

The present study aims to investigate the effects that the antioxidant and anti-inflammatory activities of clarithromycin and/or prednisolone have on experimental otitis media in effusion-induced guinea-pigs.

METHOD AND RESULTS

In this study, 35-male guinea pigs were randomly divided into five-groups. For the experimental otitis media, intra-tympanic histamine (0.1 ml) was injected into the guinea pigs in all of the groups except the control group. Then, 24-h after the intra-tympanic injections, clarithromycin (15 mg/kg/day) and/or prednisolone (1 mg/kg/day) were applied intraperitoneally to the guinea-pigs for 7-days. The biochemical analysis showed an increase in antioxidant capacity and a decrease in oxidant status and malondialdehyde (MDA) levels in the clarithromycin group and the prednisolone group and especially in the clarithromycin+prednisolone group, as compared to the experimental group (p < 0.05). In the cytokine analysis, lower levels of interleukin (IL)-6 and IL-17A and higher IL-10 were found in the clarithromycin, prednisolone, and clarithromycin+prednisolone groups than in the experimental group (p < 0.05). Furthermore, the histologic analyses showed histopathologic changes in the middle ear mucosa of the experimental group, but comparatively fewer-histopathologic changes were observed in the clarithromycin, prednisolone, and clarithromycin+prednisolone groups.

Epidermal growth factor receptor as a novel molecular target for aggressive papillary tumors in the middle ear and temporal bone

Adenomatous tumors in the middle ear and temporal bone are rare but highly morbid because they are difficult to detect prior to the development of audiovestibular dysfunction. Complete resection is often disfiguring and difficult because of location and the late stage at diagnosis, so identification of molecular targets and effective therapies is needed. Here, we describe a new mouse model of aggressive papillary ear tumor that was serendipitously discovered during the generation of a mouse model for mutant EGFR-driven lung cancer. Although these mice did not develop lung tumors, 43% developed head tilt and circling behavior. Magnetic resonance imaging (MRI) scans showed bilateral ear tumors located in the tympanic cavity. These tumors expressed mutant EGFR as well as active downstream targets such as Akt, mTOR and ERK1/2. EGFR-directed therapies were highly effective in eradicating the tumors and correcting the vestibular defects, suggesting these tumors are addicted to EGFR. EGFR activation was also observed in human ear neoplasms, which provides clinical relevance for this mouse model and rationale to test EGFR-targeted therapies in these rare neoplasms.

Antiadhesive effect of polyurethane foam packing in the guinea pig middle ear

CONCLUSIONS

No significant subepithelial healing differences were found between Gelfoam and polyurethane foam (PUF). However, levels of hyperplasia of the mucosal lining and inflammation were lower with PUF packing. PUF packing is not feasible as a middle ear packing material for abraded mucosa. Further studies are required before clinical application.

OBJECTIVE

To date, there have been few reports on the antiadhesive effect of PUF as a middle ear packing. The purpose of this study was to investigate the antiadhesive effect of PUF soaked with saline in an animal model of mucosal trauma.

METHODS

Bioresorbable PUF soaked with saline was placed over abraded mucosa in the experimental group (n = 7), and compressed Gelfoam soaked with saline was placed in the control group (n = 7). After measurement of auditory brainstem responses (ABRs), the animals were sacrificed 3 weeks after packing placement for histological observation.

RESULTS

The ABR results at postoperative week 3 showed no statistically significant difference between the preoperative and post-packing values. An adhesion pattern with subepithelial thickening was observed in the control group. Adhesion was not observed in the experimental group; however, subepithelial fibrous thickening was noted.

Effect of absorbable gelatin sponge in the middle ear: in vitro and in vivo animal model

CONCLUSION

GelitaSpon gelatin sponge (GS) showed faster reabsorption than gelfoam (GF) in vitro, and GS-packed middle ears resulted in a faster hearing recovery and less inflammation than the ears packed with GF soaked in saline. Soaking GF sponges with boric acid (BA) appeared to offset the inflammatory response of saline-soaked GF, making this inflammatory response comparable to that of GS-packed ears.

OBJECTIVE

To describe the reabsorption and inflammatory effects of absorbable gelatin sponge in the middle ear.

METHODS

For in vitro evaluation, GF and GS were used as disks immersed in saline solution or 3% BA and placed in gel. Images were captured with a microscope and processed using image processing Toolbox. For in vivo tests, 16 female albino Sprague Dawley rats were divided into four groups: bulla opening; GF + 0.9% saline; GF + BA; and GS + 0.9% saline. An anterior approach to the right bulla was used for surgery. Preoperative and postoperative auditory brainstem response thresholds were measured.

RESULTS

In vitro, there was marked degradation of GF by day 14, while GS showed complete degradation by the third day. In vivo, hearing recovery occurred by day 21. GF produced a more severe inflammatory response, which could be reduced by treating the GF with BA.

Middle ear pressure changes with sevoflurane and propofol-remifentanil

The present study aimed to compare the effects of sevoflurane (a commonly used inhalation anesthetic) and intravenous propofol on middle ear pressure (MEP) and determine the more appropriate option for middle ear operations. Fifty-seven American Society of Anesthesiologists risk class I-II patients aged 18-65 years who were not scheduled for ear or tympanic membrane operations were included in the study. The patients were randomly divided into two groups using the sealed envelope method. Propofol (0.2-0.5 mg/kg; Group P) and sevoflurane (1-2%; Group S) were used to maintain anesthesia. Baseline tympanometry was conducted on both ears and recorded before anesthesia was induced. Four additional measurements were performed and recorded at 5, 10, 15, and 30 minutes after induction. All post-induction MEP values were significantly higher than baseline measurements in Group S (P < 0.05 for all); there were no differences between post-induction and baseline measurements in Group P. At 10, 15, and 30 min post-induction, MEP values were significantly higher in Group S than in Group P (P < 0.05). Sevoflurane increased MEP values significantly compared with propofol anesthesia. We conclude that propofol can be used more reliably than sevoflurane in middle ear operations.

Combining use of captopril and losartan attenuates the progress of Streptococcus pneumoniae-induced tympanosclerosis through the suppression of TGF-β1 expression

Objectives

In this study, using an Streptococcus pneumoniae-induced tympanosclerosis (TS) model, we explored the effects of captopril and losartan in the treatment of TS and the possible mechanisms.

Study Design

A prospective experimental animal study.

Methods

We set up the TS models in both guinea pig and wistar rat by inoculation of type-3 Streptococcus pneumoniae microorganisms and then treated the animals with the combining use of captopril and losartan. Otomicroscopy was employed to observe the development of TS. Auditory brainstem response was used to test the hearing function of animals. Hematoxylin-eosin and von Kossa staining were performed to determine the morphological changes and calcium depositions. The protein expressions of transforming growth factor β1 (TGF-β1) were assessed by western blot and immunohistochemistry staining, and the mRNA level of TGF-β1 was measured by quantitative reverse transcription- polymerase chain reaction.

Results

The combining use of captopril and losartan attenuated TS responses in terms of a decrease in the TS incidence and the ABR threshold, a reduction of hyalinization and calcification in the middle ear mucosa and the thickness of the mucosa. In addition, the TGF-β1 expression was decreased at both protein and mRNA levels.

Conclusion

Our data indicate, for the first time, that the combining use of captopril and losartan obviously attenuates TS progress through inhibiting the overexpressing of TGF-β1.

Amphiphilic γ-PGA nanoparticles administered on rat middle ear mucosa produce adjuvant-like immunostimulation in vivo

CONCLUSION

Amphiphilic biodegradable nanoparticles (NPs) composed of poly(γ-glutamic acid) conjugated with L-phenylalanine ethylester (γ-PGA-Phe NPs) applied on the rat middle ear mucosa produce an inflammatory type 1 response. The observation is of relevance for the use of γ-PGA-Phe NPs as a concomitant antigen delivery system and adjuvant measure in the context of vaccinations.

OBJECTIVES

To examine effects of topical mucosal administration of γ-PGA-Phe NPs as a potentially combined antigen delivery system and adjuvant.

METHODS

γ-PGA-Phe NPs were administered on rat middle ear mucosa in a sham-controlled design and the response was monitored, focusing on soluble markers in mucosal surface liquids and on overall histopathology.

RESULTS

γ-PGA-Phe NPs produced a dose- and time-dependent inflammatory response characterized by generation of proinflammatory cytokines (IL-1α, IL-1β, IL-6, MIP-1α, and TNF-α) and associated histopathological changes.

Ototoxic effect of daptomycin applied to the guinea pig middle ear

CONCLUSION

Daptomycin applied topically at a concentration of 50 mg/ml caused mild but statistically significant hearing impairment. Outer hair cells were not damaged by daptomycin. Great care must be taken when there is a chance that daptomycin can reach the middle ear.

OBJECTIVE

Ototopic antibiotic eardrops are frequently used to treat external and middle ear infections. Daptomycin is a new anti-methicillin-resistant Staphylococccus aureus (MRSA) drug with unknown ototoxicity. The current study examined the ototoxic effect of daptomycin in topical applications to guinea pig ears.

METHODS

Twenty-three male Hartley guinea pigs (weight, 250-640 g) were divided into three groups receiving daptomycin (50 mg/ml), gentamicin (50 mg/ml, positive control), or saline solution (negative control). After insertion of a pressure-equalizing tube, pretreatment auditory brainstem responses (ABRs) were obtained. Topical solutions of 0.1 ml were applied through the tube into the middle ear twice a day for 7 days. Post-treatment ABRs were obtained 7 days after the last treatment. Hair cell loss was investigated with whole-mount cochlear surface preparations.

RESULTS

The saline-treated (negative control) group showed no deterioration of ABR threshold. The daptomycin-treated group showed mild deterioration and the gentamicin-treated group showed severe deterioration in ABR threshold. Hair cells were preserved in the daptomycin- and saline-treated groups but severely damaged in the gentamicin group.

Sevoflurane vs. TIVA in terms of middle ear pressure during laparoscopic surgery

OBJECTIVES

The aim of this study was to investigate the effects of CO2 insufflation on the pressure of the middle ear cavity (PMEC) during laparoscopic surgery under total intravenous anesthesia (TIVA) with propofol or sevoflurane as an inhalational anesthetic maintenance.

MATERIAL AND METHODS

Sixty patients who underwent laparoscopic/or non-laparoscopic surgery under general anesthesia were included in the study. For anesthetic maintenance with inhalation agents, 20 non-laparoscopic surgery patients in Group 1 were applied sevoflurane (2-2.5%). Forty patients who underwent laparoscopic surgery were randomized into two groups. Anesthesia was maintained with sevoflurane (2-2.5%) in twenty patients in Group 2 and the TIVA technique in 20 patients in Group 3. In Group 1, PMEC was measured before anesthesia, 10 and 30 min after endotracheal intubation, 10 min before extubation, and 15, 30, 60 min and 6 hours in the postoperative period. In Group 2 and 3, PMEC was measured before the anesthesia, 10 min after intubation, 10 and 30 min after CO2 insufflation, just before the CO2 elimination, 10 min before the extubation, and 15, 30, 60 min and 6 hours after extubation in the postoperative period.

RESULTS

PMEC was significantly increased in Group 1 at 10 min after intubation, at 30 min of the operation, before extubation, and at postoperative 15 and 30 min (p < 0.05). In Group 3, differences between PMECs were detected at the 30th min of insufflation (p = 0.005), and during elimination (p = 0.035) compared to the initial measurement. Generally, the values remained positive in Group 1 and negative in Group 3. There was a significant difference between Group 1 and Group 3 at 10 min after the induction (p = 0.001). There was no statistically significant difference in PMECs between Group 2 and 3 patients undergoing laparoscopic surgery.

CONCLUSIONS

Our results indicate that, in laparoscopic surgery, TIVA used for the maintenance of anesthesia did not increase the PMEC and the changes caused by sevoflurane were also in the normal range of middle ear pressures. In patients with previous ear surgery, if there is a need of classical surgical procedures in the future, sevoflurane anesthesia should not be the first choice due to its effects on PMEC, which cause it to be increased over 50 daPa, especially at 30 min after intubation. Patient characteristics including previous ear surgery should be considered in selecting the optimum anesthetic agents and technique.

[The treatment of acute inflammation of the middle ear]

The authors propose the differential approach to the treatment of acute inflammation of otitis media and otitis externa taking into consideration etiology of the disease. Its clinical form and stage. Special attention is given to the method of local treatment including the use of various eardrops. The results of their comparative assessment are presented.

Expression of RANKL and proliferation abilities of cultured human middle ear cholesteatoma epithelial cells

One of the most distinct characteristics of middle ear cholesteatomas is their capacity for bone destruction during the growth process. In this study, we examined the relationship between inflammatory mechanisms and both bone absorption and the proliferation of epithelial cholesteatoma cells. Cultured cholesteatoma epithelial cells were stimulated by lipopolysaccharide (LPS) and dexamethasone (Dex). We found that the expression of receptor activator of NF-kappaB ligand (RANKL) and Ki-67 in cultured cholesteatoma cells was increased by LPS stimulation, indicating that LPS promotes not only bone destruction but also the proliferative activities of these cells. The constitutive expression of RANKL and Ki-67 and the production of IL-6 and IL-8 were significantly inhibited by Dex treatment. Further, Dex significantly suppressed the stimulatory effects of LPS on RANKL and Ki-67 expression and on IL-6 and IL-8 production. Based on results so far, Dex likely exerts a beneficial action against acute inflammation. However, further studies might be required to assess its clinical features.

Brief hearing loss disrupts binaural integration during two early critical periods of auditory cortex development

Early binaural experience can recalibrate central auditory circuits that support spatial hearing. However, it is not known how binaural integration matures shortly after hearing onset or whether various developmental stages are differentially impacted by disruptions of normal binaural experience. Here we induce a brief, reversible unilateral conductive hearing loss (CHL) at several experimentally determined milestones in mouse primary auditory cortex (A1) development and characterize its effects ~1 week after normal hearing is restored. We find that CHL shapes A1 binaural selectivity during two early critical periods. CHL before P16 disrupts the normal coregistration of interaural frequency tuning, whereas CHL on P16, but not before or after, disrupts interaural level difference sensitivity contained in long-latency spikes. These data highlight an evolving plasticity in the developing auditory cortex that may relate to the aetiology of amblyaudia, a binaural hearing impairment associated with bouts of otitis media during human infancy.

Time-dependent middle ear pressure changes under general anaesthesia in children: N2O-O2 mixture versus air-oxygen mixture

OBJECTIVES

The aim of this study was to investigate the effects of N2O-O2 mixture (Inspired O2 30%) on middle ear pressure (MEP) in children compared with the effects of an air-oxygen mixture (Inspired O2 50%).

METHOD

The study included thirty child patients who underwent general anaesthesia for different reasons, with the exception of ENT problems and ear interventions. They were randomly divided into two groups. Group 1 (15 children: 10 male and 5 female) received a N2O-O2 mixture (Inspired O2 30%); and group 2 (15 children: 10 male and 5 female) were given an air-oxygen mixture (Inspired O2 50%). MEP was measured using a portable impedance analyser before the operation (PreO),10 minutes after intubation (10AEn), 30 minutes after intubation (30AEn), 10 minutes before extubation (10BEx), 15 minutes after the operation (PO15), 30 minutes after the operation (PO30), 1 hour after the operation (PO1h) and 6 hours after the operation (PO6h).

RESULTS

The pressure and compliance values were the same in groups 1 and 2. The pressure-time graphs for the two groups were different: in Group 2, MEP rose quickly at 10AEn and positive pressure values were seen in the middle ear. MEP then fell rapidly until the end of the surgery and lower and negative pressures (Mean -50 daPa) were observed at PO6h. In Group 1, MEP was elevated at 10AEn and positive pressure was found (but not as high as in Group 2). MEP then fell more slowly. In other words, positive pressure in the middle ear persisted longer and the middle ear was subjected to positive pressure and nitrogen over a longer period. Separate analyses were made in Groups 1 and 2 of pressure differences and of compliance values at eight measurement points using the Friedman test. Differences in pressure values were found to be statistically significant in both Group 1 (p = 0.000) and Group 2 (p = 0.000). In Group 1, all the 10AEn and 30AEn values were significantly higher than the PreO, PO30, PO1h and PO6h values. The 10BEx value was significantly higher than the PreO and PO1h values. The PO15 value was significantly higher than the PreO value. In Group 2, the PO6h value was significantly lower than the 10BEx, 10AEn and 30AEn values. The PO1h value was significantly lower than the 30AEn values. The MEP values increased in Group 1 in younger and taller children and in children receiving anaesthesia for shorter periods. MEP values increased in Group 2 in younger and taller children, and in heavier children. MEP values fell with the length of anaesthesia.

CONCLUSION

In brief anaesthesia, nitrogen was not removed from the middle ear quickly in Group 1: middle ear pressure values were higher. The nitrous oxide remained in the middle ear longer and so the possibility of ear toxicity may increase. In Group 2, 50% O2 was rapidly absorbed and removed from the middle ear and so middle ear pressure was not as high. It may be concluded that air-oxygen mixture (Inspired O2 50%) anaesthesia should be recommended as being more reliable in tympanoplasties and other middle ear interventions than a N2O-O2 mixture (Inspired O2 30%).

Inhaled toluene can modulate the effects of anesthetics on the middle-ear acoustic reflex

Toluene (Tol) is an organic solvent widely used in the industry. It is also abused as an inhaled solvent, and can have deleterious effects on hearing. Recently, it was demonstrated that Tol has both anticholinergic and antiglutamatergic effects, and that it also inhibits voltage-dependent Ca(2+) channels. This paper describes a study of the effects of inhaled Tol on rats anesthetized with isoflurane, pentobarbital, or a mixture of ketamine/xylazine. Hearing was tested using distortion product oto-acoustic emissions (DPOAEs) associated with a contralateral noise to evaluate contraction of the middle-ear muscles. This allowed us to assess the interactions between the effects of Tol and anesthesia on the central nervous system (CNS). Although both anesthetics and Tol are known to inhibit the middle-ear acoustic reflex, our data indicated that inhaled Tol counterbalances the effects of anesthetic in a dose-dependent manner. In other terms, Tol can increase the amplitude of the middle-ear reflex in anesthetized rats, whatever the nature of the anesthetic used. This indicates that inhaling Tol (a Ca(2+)-channel-blocking drug) modifies the potency of anesthesia, and thereby the amplitude of the middle-ear reflex.

Effect of caffeic acid phenethyl ester (CAPE) on H₂O₂ induced oxidative and inflammatory responses in human middle ear epithelial cells

OBJECTIVE

Acute otitis media (OM) is a common pediatric disease. Recent research into the pathogenesis of OM has focused on oxidative damage, induced by oxygen free radicals, to the middle ear mucosa along with inflammation. Caffeic acid phenethyl ester (CAPE) is a biologically active ingredient of propolis honey bees, with antioxidative and anti-inflammatory activities. The effect of CAPE on hydrogen peroxide (H(2)O(2))-induced inflammatory and oxidative reactions in the middle ear is still not known. The aim of this study was to evaluate the anti-inflammatory and antioxidative effects of CAPE on cultured human middle ear epithelial cells (HMEECs).

METHODS

The inflammatory injury of H(2)O(2) and the anti-inflammatory effect of CAPE were determined by measuring levels of pro-inflammatory cytokines (tumor necrosis factor (TNF)-α and COX-2) with real-time reverse transcription polymerase chain reaction and Western blot analysis. Oxidative stress induced by H(2)O(2) and antioxidative effects of CAPE were evaluated directly by reactive oxygen species (ROS) production using flow cytometric analysis of 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester (CM-H(2)DCFDA), and indirectly by the expression of superoxide dismutase (SOD) using Western blot analysis. The effect of CAPE was compared with N-acetyl cysteine (NAC) which has well-known antioxidative and anti-inflammatory effects.

RESULTS

CAPE significantly inhibited H(2)O(2)-induced upregulation of TNF-α and COX-2 expression in a dose and time dependent manner. ROS accumulation induced by H(2)O(2) stimulation was decreased by CAPE pretreatment. Induced SOD expression after H(2)O(2) stimulation was diminished by CAPE pretreatment. The anti-inflammatory and antioxidative effects of CAPE were similar to those of NAC.

CONCLUSIONS

These findings suggest that inflammation induced by H(2)O(2) can be inhibited by CAPE via inhibition of the expression of pro-inflammatory cytokines such as TNF-α and COX-2. Furthermore, CAPE has antioxidative effects, which decreases the need for endogenous SOD expression.

[The treatment of the patients presenting with chronic inflammation of the trepanation cavity with a preparation containing silver nanoparticles following sanitation surgery of the open type]

The objective of the present study was to estimate the efficacy of argovit used for the treatment of relapses of chronic suppurative otitis medium (CSOM) developing in the patients who underwent the sanitation surgical procedure. The study carried out between January 2011 and November 2011 included 35 patients aged from 12 to 69 years presenting with CSOM after surgical intervention on the tympanic cavity of the middle ear. The treatment resulted in the rapid elimination of clinical symptoms and positive dynamics of the objective signs of the disease, such as reduction or termination of pathological exudation and stimulation of the epidermization processes. The majority of the treated patients had stable remission within 6 months after the termination of the treatment.

[Local therapy of acute sensorinerual deafness by means of intratympanic administration of steroids]

AIM OF THE STUDY

to estimate the efficacy of local therapy of acute sensorinerual deafness by means of intratympanic administration of steroids.

PATIENTS AND METHODS

the study included 73 patients presenting with acute sensorinerual deafness (ACND). 24 of them were given local steroid therapy (through a shunt) during 6 months, another 24 patients received traditional systemic therapy, and 25 ones systemic steroid monotherapy (intravenously) for 10 days. The tonal threshold audiograms obtained before as well as 1, 3, and 6 months after the treatment were compared. It was shown that the efficacy of the intratympanic administration of steroids during 1 month was not significantly different from that of systemic therapy. The long-term therapy (for 6 months) by the intratympanic administration of steroids yielded better results than systemic therapy.

CONCLUSION

the local intratympanic administration of steroids may be used as a self-contained method for the primary treatment of acute sensorinerual deafness.

[The acceleration of remission after exacerbation of chronic suppurative otitis media following functional-reconstructive operations on the middle ear]

This study had the objective to enhance the efficacy of the surgical treatment of the patients presenting with chronic suppurative otitis media by means of reduction of the time needed to achieve persistent remission of the disease in the framework of a complex of therapeutic and rehabilitative measures making possible the surgical intervention on the middle ear regardless of the activity of the inflammatory process and its severity. Sixty five patients with chronic suppurative otitis media were examined and treated to estimate the clinical efficiency of the proposed complex of therapeutic and rehabilitative measures. It is maintained that this complex allows to achieve the positive results of reconstructive and restorative surgery without waiting for the development of long-term remission.

[The differential approach to the treatment of exudative otitis media with the use of mucosal immunocorrection]

The objective of the present study was to improve the efficacy of the treatment of the patients suffering from exudtaive otitis media (EOM). A total of 75 patients presenting with EOM were allocated to 2 groups. In one of them (n=36) the patients were treated using conventional therapeutic modalities, in the other one (n=39) with the use of a local immunomodulator (a 0.04% synthetic tetradecapeptide solution). The local application of the immunocorrective agent has demonstrated its normalizing action on the parameters of both local and systemic immunity. It is concluded that the adequate and timely treatment with the use of synthetic tetradecapeptide reduces the probability of relapse and chronization of the pathological process which not infrequently allows the surgical intervention to be avoided.

Chlorhexidine ototoxicity in ear surgery part II: survey of preparation solution used by otolaryngologists in Canada: is there a cause for concern?

OBJECTIVE

To conduct a survey of the antiseptic preparations used for ear surgeries among otolaryngologists in Canada.

METHODS

An electronic survey was sent to active members of the Canadian Society of Otolaryngology-Head and Neck Surgery via e-mail. Questions included the use of antiseptic, choice of preparation solution, duration of preparation, use of a barrier method, and compliance with hospital protocol changes.

RESULTS

The e-mail was received by 253 otolaryngologists, and 85 completed the survey. Four of 85 respondents did not perform tympanoplasty surgery and were not included in the analysis. Of those who performed tympanoplasty (n  =  81), 78 of the 81 respondents (96%) used an antiseptic preparation solution at surgery, whereas 3 respondents (4%) did not. Sixty-six of the 77 respondents (86%) used aqueous povidone-iodine, 4 (5%) used a chlorhexidine-based preparation, 3 (4%) used an alcohol-based solution, 3 (4%) used others, and 1 answered "I don't know." Thirty-eight of 75 (29%) respondents used a barrier method, 23 (31%) answered "always," 18 (24%) answered "sometimes," and 5 (7%) answered "I don't know." When asked if they would comply with a hypothetical hospital policy to use chlorhexidine in ear surgery, 15 of 79 (19%) respondents agreed, whereas 64 (81%) disagreed. Among the aqueous povidone-iodine users (n  =  66), 7 (11%) agreed to change to chlorhexidine.

CONCLUSIONS

There is a wide variation in practice in the use of surgical preparation solution among otolaryngologists performing ear surgery. Surgeons must be vigilant to avoid ototoxicity. A national society consensus on appropriate preparation solutions for ear surgery would minimize patients' risk and minimize future medicolegal actions.

Chlorhexidine ototoxicity in ear surgery, part 1: review of the literature

OBJECTIVE

Chlorhexidine is a common antiseptic used to prevent surgical infection. However, its exposure to the middle ear may lead to deafness. The mechanisms of the ototoxicity of chlorhexidine are reviewed. The importance of recognizing its toxicity cannot be overstated in preventing injury to patients undergoing ear surgery.

METHODS

A systematic literature search was performed looking at data from human and animal studies. Search engines included MEDLINE, EMBASE, The Cochrane Library, CENTRAL, CINAHL, and Web of Science to November 1, 2010, for relevant studies published in all languages. Two independent reviewers (P.L. and D.D.P.) screened the references from published articles for additional relevant studies. Medical Subject Headings and key words including intervention (chlorhexidine, antiseptic), exposure (myringoplasty, intratympanic), and adverse effects (sensorineural hearing loss, ototoxicity, vestibular toxicity) were used.

RESULTS

Twelve studies were identified, two of which were non-English and were excluded. Only 2 articles on human subjects and 12 articles on animal models concerning chlorhexidine ototoxicity were identified.

CONCLUSIONS

Chlorhexidine in both human studies and animal models demonstrates ototoxicity if it reaches the inner ear. The toxicity of chlorhexidine appears to be related to its concentration and probable contact time with the round window membrane intraoperatively. It is conceivable that the incidence of chlorhexidine toxicity may be higher than stated if unrecognized or has resulted in subsequent medicolegal actions. From the evidence available, safer preparation solutions are available without clinical risks for ototoxicity should surgeons continue with this practice.

Failure of fluorescence to reveal middle ear penetration of quinolone drops

OBJECTIVE

To evaluate the utility of fluorescence to assess penetration of quinolone ear drops (EDs) through tympanostomy tubes (TTs), the middle ear, eustachian tube, and into the oropharynx.

DESIGN

Before-and-after trial.

SETTING

Academic, tertiary care hospital.

PATIENTS

Young children undergoing TT placement for otitis media and adolescents or adults undergoing repair of tympanic membrane (TM) perforations were included.

INTERVENTIONS

Fluorescence of ofloxacin otic solution and serial dilutions was assessed with a Wood's lamp in vitro. Passage of ototopically administered ofloxacin into the pharynx was assessed in patients at the time of TT placement or TM repair. The oropharynx was visualized for fluorescence with a UV light for up to 2 hours after otic instillation.

MAIN OUTCOME MEASURE

Oropharyngeal fluorescence.

RESULTS

Ofloxacin otic fluorescence was visible at up to a 1:4 dilution. Fluorescence was confirmed in vivo by placing 1 drop of ofloxacin into the posterior pharynx and visualizing it transorally. Fluorescence was not identified in any of 20 patients after TT placement and in any of 6 patients prior to tympanoplasty. Two patients undergoing tympanoplasty reported tasting the EDs.

CONCLUSION

Fluorescence is not a satisfactory method of assessing quinolone ED penetration through TTs and TM perforations, the middle ear, and into the nasopharynx.

HIF-VEGF pathways are critical for chronic otitis media in Junbo and Jeff mouse mutants

Otitis media with effusion (OME) is the commonest cause of hearing loss in children, yet the underlying genetic pathways and mechanisms involved are incompletely understood. Ventilation of the middle ear with tympanostomy tubes is the commonest surgical procedure in children and the best treatment for chronic OME, but the mechanism by which they work remains uncertain. As hypoxia is a common feature of inflamed microenvironments, moderation of hypoxia may be a significant contributory mechanism. We have investigated the occurrence of hypoxia and hypoxia-inducible factor (HIF) mediated responses in Junbo and Jeff mouse mutant models, which develop spontaneous chronic otitis media. We found that Jeff and Junbo mice labeled in vivo with pimonidazole showed cellular hypoxia in inflammatory cells in the bulla lumen, and in Junbo the middle ear mucosa was also hypoxic. The bulla fluid inflammatory cell numbers were greater and the upregulation of inflammatory gene networks were more pronounced in Junbo than Jeff. Hif-1α gene expression was elevated in bulla fluid inflammatory cells, and there was upregulation of its target genes including Vegfa in Junbo and Jeff. We therefore investigated the effects in Junbo of small-molecule inhibitors of VEGFR signaling (PTK787, SU-11248, and BAY 43-9006) and destabilizing HIF by inhibiting its chaperone HSP90 with 17-DMAG. We found that both classes of inhibitor significantly reduced hearing loss and the occurrence of bulla fluid and that VEGFR inhibitors moderated angiogenesis and lymphangiogenesis in the inflamed middle ear mucosa. The effectiveness of HSP90 and VEGFR signaling inhibitors in suppressing OM in the Junbo model implicates HIF–mediated VEGF as playing a pivotal role in OM pathogenesis. Our analysis of the Junbo and Jeff mutants highlights the role of hypoxia and HIF–mediated pathways, and we conclude that targeting molecules in HIF–VEGF signaling pathways has therapeutic potential in the treatment of chronic OM.

Otitis media with effusion (OME) is the commonest cause of hearing loss in children, and treatment using grommets remains the commonest surgical procedure in children. Chronic forms of OM are known from human population studies to have a significant genetic component, but little is known of the underlying genes or pathways involved. We have analyzed two chronic OM mouse models, the Junbo and Jeff mutants, and have found that both demonstrate hypoxia and hypoxia-inducible factor (HIF) mediated responses. There is upregulation of inflammatory pathways in the mutant middle ears and in Junbo elevation of cytokines that modulate Hif-1α. Hif-1α levels are raised in the middle ear as well as downstream targets of HIF such as Vegfa. We explored the effects of small-molecule inhibitors of HSP90 and VEGF receptor signaling in the Junbo mutant and found significant reductions in hearing loss, the occurrence of bulla fluid, and moderation of vascular changes in the inflamed middle ear mucosa with the VEGF receptor inhibitors. The study of the Junbo and Jeff mutants demonstrates the role of hypoxia and HIF mediated pathways in OM pathogenesis, and it indicates that targeting the HIF–VEGF pathway may represent a novel approach to therapeutic intervention in chronic OM.

Prevention of cisplatin-induced hearing loss by administration of a thiosulfate-containing gel to the middle ear in a guinea pig model

PURPOSE

Thiosulfate may reduce cisplatin-induced ototoxicity, most likely by relieving oxidative stress and by forming inactive platinum complexes. This study aimed to determine the concentration and protective effect of thiosulfate in the cochlea after application of a thiosulfate-containing high viscosity formulation of sodium hyaluronan (HYA gel) to the middle ear prior to i.v. injection of cisplatin in a guinea pig model.

METHODS

The release of thiosulfate (0.1 M) from HYA gel (0.5% w/w) was explored in vitro. Thiosulfate in the scala tympani perilymph of the cochlea 1 and 3 h after application of thiosulfate in HYA gel to the middle ear was quantified with HPLC and fluorescence detection. Thiosulfate in blood and CSF was also explored. The potential otoprotective effect was evaluated by hair cell count after treatment with thiosulfate in HYA gel applied to the middle ear 3 h prior to cisplatin injection (8 mg/kg b.w.).

RESULTS

HYA did not impede the release of thiosulfate. Middle ear administration of thiosulfate in HYA gel gave high concentrations in the scala tympani perilymph while maintaining low levels in blood, and it protected against cisplatin-induced hair cell loss.

CONCLUSION

HYA gel is an effective vehicle for administration of thiosulfate to the middle ear. Local application of a thiosulfate-containing HYA gel reduces the ototoxicity of cisplatin most likely without compromising its antineoplastic effect. This provides a minimally invasive protective treatment that can easily be repeated if necessary.

Pneumococcal peptidoglycan-polysaccharides regulate Toll-like receptor 2 in the mouse middle ear epithelial cells

Toll-like receptor 2 (TLR2) plays a key role in the host defense against Gram staining positive (Gram) bacteria and their cell wall envelope components. However, little is known about the expression of TLR2 in the middle ear under otitis media (OM) conditions, and its role in the persistent otitis media with effusion (OME). In this study, we demonstrated that the pneumococcal cell wall component, peptidoglycan-polysaccharides (PGPS), activated the expression of TLR2 in the middle ear epithelial cells through the nuclear factor kappa B (NF-κB)-cytokine signaling pathway while I kappa B alpha mutant (IκBαM), a dominant negative inhibitor of NF-κB, abrogated the expression of TLR2 induced by PGPS. This study suggests that the existence of residual PGPS may maintain a low profile of cytokine production in the middle ear mucosa and thus contribute to the pathogenesis of OME.

Guggulsterone suppresses LPS induced inflammation of human middle ear epithelial cells (HMEEC)

OBJECTIVE

Guggulsterone is a bioactive constituent of resinous sap originating from the guggul tree, Commiphora mukul, which has been used over several thousands of years to treat various diseases, including atherosclerosis, rheumatism, and obesity. However, the effect of guggulsterone inflammatory reactions induced by lipopolysaccharide (LSP) is not known. The aim of this study was to evaluate the anti-inflammatory effect of guggulsterone on cultured human middle ear epithelial cells (HMEEC).

METHODS

The effect of guggulsterone on LPS-induced tumor necrosis factor-alpha (TNF-α) and cyclooxygenase-2 (COX-2) expression was evaluated in HMEEC by real-time reverse transcription polymerase chain reaction (RT-PCR). LPS-induced COX-2 production and degradation of the inhibitor kB-alpha (IkB-α) were determined by Western blot analysis.

RESULTS

Guggulsterone significantly inhibited LPS-induced upregulation of TNF-α and COX-2 in a dose-dependent manner. COX-2 protein production by LPS was significantly suppressed by the guggulsterone pretreatment. Furthermore, LPS-induced IkB-α degradation was suppressed by the guggulsterone pretreatment.

CONCLUSIONS

These results show that the guggulsterone has inhibitory effect on TNF-α expression and COX-2 production and it may be mediated through its inhibition of nuclear factor-kB activation. Our findings provide an insight into the molecular mechanisms underlying the anti-inflammatory activities of guggulsterone in relationship to otitis media.

Roles of an anti-tuberculosis medication and surgery in patients with tuberculous otitis media

CONCLUSION

The standard treatment for tuberculous otitis media (TOM) without complications consists of anti-tuberculosis (anti-TB) medication, with which we experienced good treatment outcomes. However, surgery is required for recovery of anatomy and hearing function.

OBJECTIVE

To determine the clinical characteristics of TOM that might optimize diagnosis and to evaluate the differences in clinical courses between patients treated with and without surgery.

METHODS

We analyzed 14 patients (16 ears) who had been diagnosed and treated for TOM. Radiologic findings, laboratory data, and audiometry results were also evaluated. Patients were divided into a chemotherapy group and a surgery group according to treatment modality.

RESULTS

Temporal bone CT (TBCT) showed total occupation of the tympanic cavity by soft tissue and little evidence of ossicular erosion. In the chemotherapy group, dry ears were obtained in all but one patient (14 ears) after treatment. Normalized tympanic membrane (TM) was found in 50% in the chemotherapy group and in 75% in the surgery group. The air-bone gap (ABG) changed from 40.3 +/- 2.5 dB to 47.0 +/- 19.2 dB in the chemotherapy group and from 35.2 +/- 7.6 dB to 30.2 +/- 11.4 dB in the surgery group. After treatment, ABG improved by > 10 dB in one ear in the chemotherapy group and in four ears in the surgery group.

[Middle ear packing with collagen-polyvinylpyrrolidone sponge. Experimental study in guinea pigs]

INTRODUCTION

Packing material is mandatory in middle ear (ME) surgery in order to avoid inflammation, adhesions and fibrotic healing. Collagen polivynil-pirrolidone (CPVP) is a healing modulator, which reduces inflammation and fibrosis. Hence we can hypothesize that packing of the ME with CPVP sponge will lead a good ME healing.

OBJECTIVE

The aim of this study was to evaluate the otoscopic and microscopic changes induced on the healthy mucosa of the ME and Tympanic membrane (TM) after packing with CPVP sponge in guinea pigs.

MATERIAL AND METHODS

Twelve guinea pigs were operated on of right myringotomy. The ME was packed with: Group I (n = 6): Absorbable gelatin sponge (AGS) in SS; Group II (n = 6): CPVP soaked in SS. TM and ME integrity was evaluated otoscopically, as well as residual packing material. Euthanasia was performed on the 4th post-operative week. ME mucosa histologic examination was done.

RESULTS

Group I in all the cases showed residual packing material (p < 0.007 Student's test p < 0.001 ANOVA). Histologically both groups presented inflammation with polymorphonuclears, in addition group I showed severe lymphocytosis (p < 0.003 Student's, test p < 0.001, ANOVA).

CONCLUSION

The CPVP sponge when it is used as material of packing in the OM of guinea pigs produces less chronic inflammatory changes, but more studies with the injured mucosa are required to validate their utility in the otologic surgery.

Does exogenous nitric oxide influence tympanosclerosis? An experimental study

OBJECTIVE

We aimed to elucidate the effects of exogenous nitric oxide application via myrigotomized rat tympanic membranes on tympanosclerosis.

MATERIALS AND METHODS

Forty male rats were included in the study. After myringotomy, nitric oxide was given to the left tympanic cavities and saline was given to the right as the control group. The procedure was repeated 3 times with weekly intervals. Three months after the first procedure, otomicroscopic examination was made and the rats were sacrificed for histologic examination.

RESULTS

Neither otomicroscopic examination, nor histologic examination of middle ears and tympanic membranes revealed any significant difference between the right and left sides. Tympanic membrane thicknesses were also similar on both sides without showing any significant difference.

CONCLUSIONS

Data from this study indicate that exogenous nitric oxide application did not change the occurence of tympanosclerosis in the rat model. Other cytokine interactions are needed to start the reaction sequence leading to tympanosclerosis.

[The rhinogenic deafness and SPA therapy: clinical-experimental study]

OBJECTIVES

The sulphur SPA inhalation therapy is useful in respiratory and otolaryngologic chronic inflammatory diseases in adult subjects and children. The therapeutic action relies on anti-inflammatory, mucolytic and trophic effects. Particularly in children, the sulphur SPA inhalation therapy, using endotympanic ventilation or Politzer method, would be suitable in the treatment of the rhinogenic deafness. Several reports have demonstrated the effectiveness of endotympanic ventilation while the results on the Politzer method are inconclusive. On the basis of these considerations, aim of our study was to analyze the effectiveness and the safety of the aerosol+Politzer with a sulphur mineral water in children affected by rhinogenic deafness or chronic inflammatory processes responsible for the onset or persistence of rhinogenic deafness.

PATIENTS AND METHODS

The study has been performed on 23 subjects in pediatric age (61% women and 39% males; mean age: 6+/-2.4 years; age range: 3-14 years) affected by chronic catarrhalis otitis, chronic rhino-pharyngitis inflammations, chronic or recurrent adenoiditis with dysfunction of the Eustachian Tube. The investigated subjects underwent 12 consecutive days sulphur SPA inhalation therapy (aerosol+Politzer) at the Terme of Stabia in Castellammare (Naples, Italy). At the beginning and at the end of the SPA cycle the functionality of the middle ear and the tolerability were evaluated.

RESULTS

The results have shown an increase of the impedance curves that correspond to the normal ventilation of the tympanic box (type A (13% before therapy and of 57% post-therapy) and a decrease of the pathological curves of type B and type C (87% pre-therapy and of 43% post-therapy); a significant increase of compliance (p 0.05) in pathological curves of type B and C. No adverse reaction to the SPA inhalation therapy has been reported during the study.

CONCLUSIONS

In concordance with the literature our data demonstrated that the sulphur SPA inhalation treatment induce a improvement of middle ear function of the subjects examined with good local and systemic tolerability.

Results of intratympanic dexamethasone injection as salvage treatment in idiopathic sudden hearing loss

OBJECTIVE

To evaluate the efficacy of intratympanic (IT) dexamethasone injection as a salvage treatment in idiopathic sudden hearing loss (ISHL) patients.

DESIGN

A prospective study.

SETTING

A secondary care hospital.

METHODS

Fifty-two subjects whose pure-tone averages (PTAs) after a 2-week standard treatment were > 30 dB or worse than 10 dB from the contralateral ear were included. Thirty-four patients underwent IT dexamethasone injection and 18 patients (control) received no further treatment. Final hearing outcome was compared between the two groups.

MAIN OUTCOME MEASURES

At 2 weeks after IT dexamethasone injection, audiograms were obtained and compared between the two groups.

RESULTS

Sixteen patients (47.1%) in the IT dexamethasone group and 8 patients (44.4%) in the control group finally showed an improvement of 10 dB or more in PTA or a 15% or more change in speech discrimination score (p > .05). The average improvement in PTAs was 8.2 dB in the IT dexamethasone group and 3.6 dB in the control group (p = .184). Patients responsive to the initial treatment showed better final outcomes, irrespective of IT dexamethasone injection.

CONCLUSIONS

The present study does not support IT dexamethasone injection as a beneficial salvage treatment for ISHL patients. The true efficacy of this procedure still needs to be investigated.

Therapeutic effectiveness over time of intratympanic dexamethasone as salvage treatment of sudden deafness

CONCLUSION

Intratympanic dexamethasone (ITD) within 1 month after initial treatment failure should be utilized as salvage treatment for refractory sudden sensorineural hearing loss (SSNHL).

OBJECTIVE

To investigate the therapeutic efficacy over time of ITD as salvage treatment in SSNHL.

MATERIALS AND METHODS

We retrospectively reviewed the medical records and audiograms of 99 SSNHL patients who were refractory to 2 weeks of oral steroid treatment, from August 2003 to October 2006. Patients were divided into those receiving no further treatment (control group) and those receiving ITD within 2 weeks (early-ITD), between 2 weeks and 1 month (mid-ITD), and between 1 and 2 months (late-ITD) after initial treatment failure. ITD was performed in the supine position on four separate occasions over the course of 2 weeks. Final assessment of hearing was carried out 3 months after outbreak of SSNHL. Hearing improvement was defined as a > 15 dB decrease in four-tone average (FTA).

RESULTS

Overall hearing improvement was observed in 8 of 50 (16.0%) control patients, 7 of 16 (43.8%) early ITD patients, 6 of 20 (30.0%) mid ITD patients, and 2 of 13 (15.4%) late ITD patients.

Medical treatment of otosclerosis: rationale for use of bisphosphonates

Otosclerosis is a bony dyscrasia characterized by histopathological findings of osteoclast production. Osteoclastogenesis explains the pathogenesis of otosclerosis. Basic science research in the experimental animal otic capsule has given insight into the process of evolution of otosclerosis. The normal otic capsule is preserved with very little bone turnover as a result of the production of osteoprotegerin (OPG) by the membranous inner ear that prevents the activation of osteoclasts. Animals genetically unable to produce OPG demonstrated the production of hearing loss and histopathology of the temporal bones consistent with that seen in otosclerosis. Applying the understanding of osteoclastogenesis to the treatment of otosclerosis has led to the clinical use of the class of drugs called bisphosphonates. The bisphosphonate group of drugs specifically targets osteoclasts by reducing production of osteoclasts and accelerating their early cell death. The rationale for use of bisphosphonates to treat the sensorineural hearing loss of otosclerosis is explained, with cases that illustrate the bisphosphonates treatment algorithms and the response to treatment.

Effects of desflurane on middle ear pressure

OBJECTIVE

To evaluate the effects of desflurane on middle ear pressure.

STUDY DESIGN

A prospective clinical study.

METHODS

In this study, 38 ears of 19 male children that were scheduled for circumcision were included. Baseline tympanometry reading was performed on each ear just before anesthesia. After induction anesthesia with propofol a laryngeal mask was applied and desflurane administration was started. The next tympanometry reading was taken at 5th, 10th and 15th minute after administration and at the 10th minute after the cessation of desflurane. Data were analysed using Wilcoxon test.

RESULTS

Mean MEP values before anesthesia in 38 ears of 19 boys were -10.32+/-33.14. After starting the administration of desflurane 5th minute mean value was 71.15+/-60.42, at the 10 th minute 111.56+/-59.03 and at the 15th minute it increased to 120.50+/-54.14, and these measurements were significantly higher than the starting value (p<0.001). After cessation of desflurane mean MEP value dropped to 57.56+/-79.06, but compared with the starting value this was also significantly higher (p<0.001).

CONCLUSION

Desflurane may increase the middle ear pressure and it may be unsuitable for certain middle ear surgeries.

Intratympanic application of botulinum toxin: experiments in guinea pigs for excluding ototoxic effects

The aim of the study was to exclude ototoxic side effects of intratympanally applied botulinum toxin. The background is that a transection of the tensor tympani tendon (tenotomy) may relieve symptoms of tinnitus due to myoclonic tensor contractions. Moreover, there are certain indications that in some cases tenotomy may influence the course of Menière's disease positively. In such cases, a temporary (probatory) inactivation of the muscle with botulinum toxin might be better than a definitive surgical solution. Although in theory botulinum toxin should not have ototoxic side effects, a study on animals (guinea pigs) should prove this assumption. On eight guinea pigs (16 ears), the middle ear spaces (bullae) were opened and botulinum toxin was introduced. Hearing thresholds were measured via ABR recordings, prior to 1 and 3 weeks, respectively, after botulinum toxin application. Histological examinations of the middle ear mucosa were performed on each animal. In our series, the hearing thresholds remained essentially unchanged. Furthermore, no middle ear pathologies could be found in histology. No negative effects of botulinum toxin on hearing could be observed in our series. This is a precondition for the further development of the concept of intratympanical applications of the drug, to inactivate the tensor tympani muscle or for other options.

Interleukin-1beta upregulates Na+-K+-2Cl- cotransporter in human middle ear epithelia

Disruption of periciliary fluid homeostasis is the main pathogenesis of otitis media with effusion (OME), one of the most common childhood diseases. Although the underlying molecular mechanisms are unclear, it has been suggested that the altered functions of ion channels and transporters are involved in the fluid collection of middle ear cavity of OME patients. In the present study, we analyzed the effects of a major cytokine interleukin (IL)-1beta, which was known to be involved in the pathogenesis of OME, on Na(+)-K(+)-2Cl(-) cotransporter (NKCC) in human middle ear cells. Intracellular pH (pH(i)) was measured in primary cultures of normal human middle ear epithelial (NHMEE) cells using a double perfusion chamber, which enabled us to analyze the membrane-specific transporter activities. NKCC activities were estimated by the pH(i) reduction due to bumetanide-sensitive intracellular uptake of NH(4) (+). In NHMEE cells, NKCC activities were observed only in the basolateral membrane, and immunoblotting using specific antibodies revealed the expression of NKCC1. Interestingly, IL-1beta treatments augmented the basolateral NKCC activities and increased NKCC1 expression. In addition, IL-1beta treatments stimulated bumetanide-sensitive fluid transport across the NHMEE cell monolayers. Furthermore, an elevated NKCC1 expression was observed in middle ear cells from OME patients when compared to those from control individuals. The above results provide in vitro and in vivo evidence that the inflammatory cytokine IL-1beta upregulates NKCC1 in middle ear epithelial cells, which would be one of the important underlying mechanisms of excess fluid collection in OME patients.

Ototoxic Effect of Burow Solution Applied to the Guinea Pig Middle Ear

OBJECTIVE

To analyze the ototoxicity of Burow solution as an otologic preparation.

BACKGROUND

Burow solution has been used for years in the treatment of acute or chronic otitis externa and chronic suppurative otitis media. This acidic solution has antibacterial and antiedematous properties. Ototoxic effect of Burow solution has not been known, so the current study was designed to observe the ototoxic effect of Burow solution experimentally.

MATERIALS AND METHODS

Experiments were performed in 32 young, male albino guinea pigs (weight, 450-550 g). Twenty animals in the experimental group were divided into 2 groups of 10 animals each. The first group received 13% Burow solution (13% aluminum subacetate), and the second received 4% Burow solution (4% aluminum subacetate). Twelve animals in the control group were divided into 2 groups of 6 animals each. The first group received gentamicin (40 mg/mL; ototoxic control), and the second received saline solution (negative control). Under general anesthesia, pretreatment auditory brainstem responses (ABRs) from the right ear were obtained from the animals in all groups. The right tympanic membranes were widely perforated, and a small piece of Gelfoam was applied to the middle ear. Ear solutions at concentrations of 0.1 mL were applied through transcanal approach to the middle ear twice a day in 10 days. Under general anesthesia, the Gelfoam was removed from the right middle ear, and posttreatment ABRs were obtained 14 days later after the initial time in all groups.

RESULTS

Baseline ABR results were normal in right ears of all animals tested. Animals undergoing placement of Gelfoam with either 13% Burow solution, 4% Burow solution, or saline in the middle ear showed no changes in ABR threshold. The gentamicin group showed significant change in the ABR threshold.

CONCLUSION

Burow solution was considered to be an effective and safe otologic preparation.

Safety of ofloxacin (OFLX) and fosfomycin sodium (FOM) ear drops

OBJECTIVE

The objective of this study is to evaluate the safety of two ear drops, Ofloxacin (OFLX: Taribid Otic Solution, Daiichi Seiyaku) and Fosfomycin sodium (FOM: Fosmicin S, Meiji Seiyaku).

METHODS

Albino guinea pigs were used as experimental animals, and the ototoxicity was evaluated by means of threshold changes in the compound action potentials (CAP), when topically applied to the middle ear cavity of the guinea pig. The sound stimuli applied were; click sound, with tone bursts of 8 kHz, 4 kHz, and 2 kHz. In one group of animals, after one application of the ear drops in the right middle ear cavity, the change in CAP was compared with a contralateral saline control at 24h, one week, and four weeks. In other group of animals, the ear drops were applied into the middle ear cavity for seven consecutive days and the CAP was measured at 24h.

RESULTS

At 24h the CAP threshold for click, 8 and 4 kHz elevated significantly for both the saline and ear drop treatment, but the threshold returned to normal when measured at 7 days and 28 days. Seven consecutive days of ear drops administration resulted in no reduction in the CAP for either ear drops.

CONCLUSIONS

Based on the lack of changes in the CAP, these two ear drops studied did not show any significant ototoxicities.

[Effect of poloxamer 407 on the middle ear and inner ear after regional perfusion in guinea pigs]

OBJECTIVE

To observe the biodegradation and absorption of poloxamer 407 in vivo, and the effect of poloxamer 407 on the middle ear and inner ear after regional perfusion in guinea pigs.

METHODS

The right ears of 10 guinea pigs as experimental group were perfused with 20% poloxamer 407 in situ gel 100 microl in round window niche, with the left ears as control group with normal saline. Another two animals without treatment were in negative control group. Auditory function was investigated before and 3, 7, 14, 28, 49 days after perfusion, and the histology of bulles after auditory brainstem response (ABR) each examination were examined by means of serial section after paraffin imbedding.

RESULTS

The poloxamer gel was almost biodegraded and discharged 49 days after perfusion, only few gel remained in the middle ear cavity under light microscope. The ABR threshold to filtered clicks was elevated after perfusion with poloxamer 407, and was recovered to normal at 49 days after perfusion. The morphology of the mucosa of middle ear cavity, round window membrane, Corti's and vestibular organs were not significantly damaged after poloxamer 407 perfusion.

CONCLUSIONS

Poloxamer 407 can be biodagraded in vivo or discharged via eustachian tube, and causes no inflammation on the middle ear cavity. There are temporary changes on auditory function of inner ear after topical perfusion with poloxamer 407 in round window can cause, but no irreversible damage on function and morphology of cochlear and vestibular organs.

Clear Tinnitus, middle-ear pressure, and tinnitus relief: a prospective trial

GOAL

Our goal was to establish the efficacy, in a 12-week period, of Clear Tinnitus for tinnitus relief in patients with tinnitus of the severe, disabling type.

HYPOTHESIS

We hypothesized that tinnitus relief with Clear Tinnitus reflects improvement in the sensory component of the tinnitus complaint by controlling the factor of aeration of the middle ears and improving eustachian tube function.

METHOD

In a prospective clinical trial of a homeopathic preparation--Clear Tinnitus--we attempted to identify in 15 tinnitus patients (14 male, 1 female; mean age, 47.6 years) its clinical efficacy for establishing tinnitus relief for a 3-month period. We employed a descriptive data analysis method across dimensions of risk to evaluate a base of multidimensional evidence and establish support for our hypothesis. A medical-audiological tinnitus patient protocol completed by each patient identified the clinical type of tinnitus as predominantly cochlear, with a central and middle-ear component bilaterally. We identified fluctuation in middle-ear pressure (MEP) via patients' clinical history, supported by physical examination and established with tympanometry, as a factor influencing the clinical course of the tinnitus in each patient.

RESULTS

Eleven of 15 patients completed the study. Seven responders reported tinnitus relief; four did not respond. Descriptive data analysis failed to detect any trends in a change in response with audiometric tests across the hearing spectrum; thus, we could derive no coefficients of hearing change. Evaluation revealed high-frequency tinnitus in 11 patients. The Feldmann masking curve comparison at the start and end of the study showed no significant change in the 11 patients. There was no significant alteration in the minimum masking levels or loudness discomfort levels before and after the study. Tympanometry and MEP measurement indicated a significant difference in MEP with an improvement on average of -58.18 in the right ear and -40.90 in the left ear for the 11 patients. Quantitative electroencephalography analysis revealed a marked difference in the number of significant abnormal recordings between the different frequency bands, with the delta band significantly higher than the theta, alpha, and beta bands for both the overall cohort of patients (n = 11) and those reporting tinnitus relief (n = 7). The tinnitus outcome questionnaires--the tinnitus intensity index, the tinnitus annoyance index, and the tinnitus reaction questionnaire--revealed a significant difference for the patients (7 of 11) obtaining tinnitus relief. Results of the tinnitus stress test, the tinnitus handicap index, and the measurement of depression scale before and after the study were not statistically significant.

CONCLUSIONS

Patients who completed the study demonstrated with tympanometry a statistical and clinical significance in MEP improvement or maintenance of MEP (or both). Patients with tinnitus of the severe disabling type selected for this study and responding to Clear Tinnitus reported tinnitus relief accompanied by improvement in or maintenance of MEP of the middle ears. The statistical and clinical significance of Clear Tinnitus for establishing tinnitus relief remains to be established with a larger cohort of tinnitus patients.

Topical Application of Mitomycin C to the Middle Ear Is Ototoxic in the Gerbil

HYPOTHESIS

Mitomycin C is ototoxic when applied topically to the structures of the middle ear.

BACKGROUND

Mitomycin C is a topically applied medication widely used in a variety of surgical procedures to prevent excessive scar tissue formation. Its safety for use during otologic procedures has not been fully evaluated.

METHODS

A laboratory study was undertaken using the Mongolian gerbil as an animal model. Both acute and chronic effects on cochlear function of mitomycin C were assessed with measurements of compound action potential (CAP) thresholds of the auditory nerve, CAP input/output functions, distortion product otoacoustic emissions, and endocochlear potentials. Morphologic changes were assessed with light microscopy using hematoxylin-eosin staining as well as transmission electron microscopy.

RESULTS

Five-minute applications of mitomycin C (0.5 mg/ml) to the entire surface of the middle ear adversely affected CAP thresholds, input/output functions, distortion product otoacoustic emissions, and the endocochlear potential. Ninety-minute exposures of mitomycin C solely to the round window produced similar changes. Histologic evaluation of animals 1 week after treatment showed damage to cochlear hair cells, the stria vascularis, and spiral ganglion neurons when compared with controls.

CONCLUSION

Mitomycin C can produce substantial sensorineural hearing loss when applied topically to the gerbil middle ear for even brief periods. Consequently, its safety for topical use in the human middle ear is highly questionable.